In deployment of cellular radio networks, a base station is needed to be placed for each region that requires coverage. Prior deployment strategies assumed a regular cell topology, resulting in the emplacement of radio base stations according to a strict geometric pattern. However, in real-world deployments, identically-sized cells are ill-suited to providing effective coverage because of topological features (i.e., mountains, hills, highways, etc.), and because of varying population density patterns, among other reasons.
To handle these varying characteristics, strategies involving multiple cell sizes have been proposed. For example, a traditional macro cell base station may be used to cover a relatively large area, but may be supplemented in an area of increased population density by a micro-cell (covering a smaller area than a macro-cell), a femto-cell (covering a smaller area than a micro-cell, such as a single building), or a mobile base station.
However, integration of these base stations of various sizes causes interference between cells. This is particularly true because micro-cells and other smaller cells are often placed in a location that overlaps substantially or completely with the coverage area of a macro cell. The micro cell base station and the macro cell base station may end up competing for radio resources and reducing the effectiveness of attached mobile nodes via inter-cell interference. Techniques are needed to cancel this interference and to enable multiple cells to coexist and provide enhanced service.